BOX 1-2Characterizing Cognitive Aging

• Key Features:
  • Inherent in humans and animals as they age.
  • Occurs across the spectrum of individuals as they age regardless of initial cognitive function.
  • Highly dynamic process with variability within and between individuals.
  • Includes some cognitive domains that may not change, may decline, or may actually improve with aging, and there is the potential for older adults to strengthen some cognitive abilities.
  • Only now beginning to be understood biologically, yet clearly involves structural and functional brain changes.
  • Not a clinically defined neurological or psychiatric disease such as Alzheimer's disease and does not inevitably lead to neuronal death and neurodegenerative dementia (such as Alzheimer's disease).
• Risk and Protective Factors:
  • Health and environmental factors over the life span influence cognitive aging.
  • Modifiable and non-modifiable factors include genetics, culture, education, medical comorbidities, acute illness, physical activity, and other health behaviors.
  • Cognitive aging can be influenced by development beginning in utero, infancy, and childhood.
• Assessment:
  • Cognitive aging is not easily defined by clear thresholds on cognitive tests since many factors—including culture, occupation, education, environmental context, and health variables (e.g., medications, delirium)—influence test performance and norms.
  • For an individual, cognitive performance is best assessed at several points in time.
• Impact on Daily Life:
  • Day-to-day functions, such as driving, making financial and health care decisions, and understanding instructions given by health care professionals, may be affected.
  • Experience, expertise, and environmental support aids (e.g., lists) can help compensate for declines in cognition.
  • The challenges of cognitive aging may be more apparent in environments that require individuals to engage in highly technical and fast-paced or timed tasks, in situations that involve new learning, and in stressful situations (i.e., emotional, physical, or health-related), and may be less apparent in highly familiar situations.